湿地甲烷排放研究进展

甲烷是一种仅次于二氧化碳的重要温室气体,对全球变暖的贡献率为25%。近年来大气中甲烷浓度显著增加,湿地甲烷释放量约占全球甲烷通量的20%,是大气甲烷的主要自然来源之一。甲烷主要通过产甲烷菌在厌氧条件下产生,在氧化条件下,甲烷通过土壤中的甲烷氧化菌氧化,并通过气泡、扩散和植物传输三种途径释放到大气。湿地甲烷通量在时间和空间两个方面有较大的变化,这与甲烷产生、氧化和传输过程有关,同时受到不同环境因素的影响,如:土壤质地、氧化还原电位、有机物、土壤酸碱度、植被条件、气候因素、农业管理措施等。文章还对湿地甲烷排放的观测方法和排放模型进行了简单介绍,并对今后的研究提出了几点建议。

Advances in the Research on Methane Emissions from Wetlands

Methane(CH_4) is an important greenhouse gas,which contributes 25% to the global warming,only second to carbon dioxide(CO_2).Its concentration in the atmosphere has increased greatly in last decades.Wetlands account for about 20% of the global methane flux,and are the main sources of methane in atmosphere.Methane is mainly produced by methanogenis under anaerobic conditions,oxidized by soil bacteria under aerobic conditions,and transported to atmosphere by diffusion,ebullition and aerenchymal plants.There are spatial and temporal variations among methane fluxes emission from different kinds of wetlands,which was associated with CH_4 production,oxidation and transportation on methane,and influenced by the environment factors,such as soil texture,soil organic matter,pH,Eh,plants,climates,and agricultural managements etc..The recent progresses in the measurement methods,the processes and impact factors of wetland CH_4 emission were reviewed,and suggestions for future research were put forward.